chat.go/chatserver.go

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package main
// TODO learn more about chan chan's
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// http://marcio.io/2015/07/handling-1-million-requests-per-minute-with-golang/
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import (
"bufio"
"bytes"
"crypto/rand"
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"crypto/subtle"
"encoding/base64"
"flag"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"net/url"
"os"
"path"
"strconv"
"strings"
"sync"
"time"
"github.com/emicklei/go-restful"
"gopkg.in/yaml.v2"
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)
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// I'm not sure how to pass nested structs, so I de-nested this.
// TODO Learn if passing nested structs is desirable?
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type Conf struct {
Port uint `yaml:"port,omitempty"`
Mailer ConfMailer
RootPath string `yaml:"root_path,omitempty"`
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}
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type ConfMailer struct {
Url string `yaml:"url,omitempty"`
ApiKey string `yaml:"api_key,omitempty"`
From string `yaml:"from,omitempty"`
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}
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type tcpUser struct {
bufConn bufferedConn
userCount chan int
email string
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newMsg chan string
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}
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// So we can peek at net.Conn, which we can't do natively
// https://stackoverflow.com/questions/51472020/how-to-get-the-size-of-available-tcp-data
type bufferedConn struct {
r *bufio.Reader
rout io.Reader // See https://github.com/polvi/sni/blob/master/sni.go#L135
net.Conn
}
func newBufferedConn(c net.Conn) bufferedConn {
return bufferedConn{bufio.NewReader(c), nil, c}
}
func (b bufferedConn) Peek(n int) ([]byte, error) {
return b.r.Peek(n)
}
func (b bufferedConn) Buffered() int {
return b.r.Buffered()
}
func (b bufferedConn) Read(p []byte) (int, error) {
if b.rout != nil {
return b.rout.Read(p)
}
return b.r.Read(p)
}
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// Just making these all globals right now
// because... I can clean it up later
type myMsg struct {
sender net.Conn
Message string `json:"message"`
ReceivedAt time.Time `json:"received_at"`
Channel string `json:"channel"`
User string `json:"user"`
}
type JsonMsg struct {
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Messages []*myMsg `json:"messages"`
}
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type chatHist struct {
msgs []*myMsg
i int
c int
}
var myChatHist chatHist
var broadcastMsg chan myMsg
var newConns chan net.Conn
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var wantsServerHello chan bufferedConn
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var authTcpChat chan tcpUser
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var delTcpChat chan tcpUser
var gotClientHello chan bufferedConn
var demuxHttpClient chan bufferedConn
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var delHttpChat chan bufferedConn
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var newAuthReqs chan authReq
var valAuthReqs chan authReq
var delAuthReqs chan authReq
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func usage() {
fmt.Fprintf(os.Stderr, "\nusage: go run chatserver.go\n")
flag.PrintDefaults()
fmt.Println()
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os.Exit(1)
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}
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// https://blog.questionable.services/article/generating-secure-random-numbers-crypto-rand/
func genAuthCode() (string, error) {
n := 12
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b := make([]byte, n)
_, err := rand.Read(b)
// Note that err == nil only if we read len(b) bytes.
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if err != nil {
return "", err
}
return base64.URLEncoding.EncodeToString(b), nil
}
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// Trying to keep it slim with just one goroutine per client for reads and one goroutine per client for writes.
// Initially I was spawning a goroutine per write, but my guess is that constantly allocating and cleaning up 4k
// of memory (or perhaps less these days https://blog.nindalf.com/posts/how-goroutines-work/) is probably not
// very efficient for small tweet-sized network writes
// Auth & Reads
func handleTelnetConn(bufConn bufferedConn) {
// TODO
// What happens if this is being read from range
// when it's being added here (data race)?
// Should I use a channel here instead?
// TODO see https://jameshfisher.com/2017/04/18/golang-tcp-server.html
var email string
var code string
var authn bool
// Handle all subsequent packets
buffer := make([]byte, 1024)
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var u *tcpUser
for {
//fmt.Fprintf(os.Stdout, "[raw] Waiting for message...\n")
count, err := bufConn.Read(buffer)
if nil != err {
if io.EOF != err {
fmt.Fprintf(os.Stderr, "Non-EOF socket error: %s\n", err)
}
fmt.Fprintf(os.Stdout, "Ending socket\n")
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if nil != u {
delTcpChat <- *u
}
break
}
buf := buffer[:count]
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// Rate Limit: Reasonable poor man's DoS prevention (Part 1)
// A human does not send messages super fast and blocking the
// writes of other incoming messages to this client for this long
// won't hinder the user experience (and may in fact enhance it)
// TODO: should do this for HTTP as well (or, better yet, implement hashcash)
time.Sleep(150 * time.Millisecond)
// Fun fact: if the buffer's current length (not capacity) is 0
// then the Read returns 0 without error
if 0 == count {
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fmt.Fprintf(os.Stdout, "[SANITY FAIL] using a 0-length buffer")
break
}
if !authn {
if "" == email {
// Indeed telnet sends CRLF as part of the message
//fmt.Fprintf(os.Stdout, "buf{%s}\n", buf[:count])
// TODO use safer email testing
email = strings.TrimSpace(string(buf[:count]))
emailParts := strings.Split(email, "@")
if 2 != len(emailParts) {
fmt.Fprintf(bufConn, "Email: ")
continue
}
// Debugging any weird characters as part of the message (just CRLF)
//fmt.Fprintf(os.Stdout, "email: '%v'\n", []byte(email))
// Just for a fun little bit of puzzah
// Note: Reaction times are about 100ms
// Procesing times are about 250ms
// Right around 300ms is about when a person literally begins to get bored (begin context switching)
// Therefore any interaction should take longer than 100ms (time to register)
// and either engage the user or complete before reaching 300ms (not yet bored)
// This little ditty is meant to act as a psuedo-progress bar to engage the user
// Aside: a keystroke typically takes >=50s to type (probably closer to 200ms between words)
// https://stackoverflow.com/questions/22505698/what-is-a-typical-keypress-duration
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wg := sync.WaitGroup{}
wg.Add(1)
go func() {
time.Sleep(50 * time.Millisecond)
const msg = "Mailing auth code..."
for _, r := range msg {
time.Sleep(20 * time.Millisecond)
fmt.Fprintf(bufConn, string(r))
}
time.Sleep(50 * time.Millisecond)
wg.Done()
}()
if "" != config.Mailer.ApiKey {
wg.Add(1)
go func() {
code, err = sendAuthCode(config.Mailer, strings.TrimSpace(email))
wg.Done()
}()
} else {
code, err = genAuthCode()
}
wg.Wait()
if nil != err {
// TODO handle better
// (not sure why a random number would fail,
// but on a machine without internet the calls
// to mailgun APIs would fail)
panic(err)
}
// so I don't have to actually go check my email
fmt.Fprintf(os.Stdout, "\n== TELNET AUTHORIZATION ==\n[cheat code for %s]: %s\n", email, code)
time.Sleep(150 * time.Millisecond)
fmt.Fprintf(bufConn, " done\n")
time.Sleep(150 * time.Millisecond)
fmt.Fprintf(bufConn, "Auth Code: ")
continue
}
if code != strings.TrimSpace(string(buf[:count])) {
fmt.Fprintf(bufConn, "Incorrect Code\nAuth Code: ")
} else {
authn = true
time.Sleep(150 * time.Millisecond)
fmt.Fprintf(bufConn, "\n")
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u = &tcpUser{
bufConn: bufConn,
email: email,
userCount: make(chan int, 1),
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newMsg: make(chan string, 10), // reasonably sized
}
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authTcpChat <- *u
// prevent data race on len(myRawConns)
// XXX (there can't be a race between these two lines, right?)
count := <-u.userCount
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close(u.userCount)
u.userCount = nil
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// Note: There's a 500ms gap between when we accept the client
// and when it can start receiving messages and when it begins
// to handle them, however, it's unlikely that >= 10 messages
// will simultaneously flood in during that time
time.Sleep(50 * time.Millisecond)
fmt.Fprintf(bufConn, "\n")
time.Sleep(50 * time.Millisecond)
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fmt.Fprintf(bufConn, "\033[1;32m"+"Welcome to #general (%d users)!"+"\033[22;39m", count)
time.Sleep(50 * time.Millisecond)
fmt.Fprintf(bufConn, "\n")
time.Sleep(50 * time.Millisecond)
// TODO /help /join <room> /users /channels /block <user> /upgrade <http/ws>
//fmt.Fprintf(bufConn, "(TODO `/help' for list of commands)")
time.Sleep(100 * time.Millisecond)
fmt.Fprintf(bufConn, "\n")
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// Would be cool to write a prompt...
// I wonder if I could send the correct ANSI codes for that...
//fmt.Fprintf(bufConn, "\n%s> ", email)
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go handleTelnetBroadcast(u)
}
continue
}
//fmt.Fprintf(os.Stdout, "Queing message...\n")
//myRooms["general"] <- myMsg{
broadcastMsg <- myMsg{
ReceivedAt: time.Now(),
sender: bufConn,
Message: string(buf[0:count]),
Channel: "general",
User: email,
}
//fmt.Fprintf(bufConn, "> ")
}
}
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// Writes (post Auth)
func handleTelnetBroadcast(u *tcpUser) {
for {
msg := <-u.newMsg
// Disallow Reverse Rate Limit: Reasonable poor man's DoS prevention (Part 3)
// https://blog.cloudflare.com/the-complete-guide-to-golang-net-http-timeouts/
timeoutDuration := 2 * time.Second
u.bufConn.SetWriteDeadline(time.Now().Add(timeoutDuration))
_, err := fmt.Fprintf(u.bufConn, msg)
if nil != err {
delTcpChat <- *u
break
}
}
}
func muxTcp(conn bufferedConn) {
// Wish List for protocol detection
// * PROXY protocol (and loop)
// * HTTP CONNECT (proxy) (and loop)
// * tls (and loop) https://github.com/polvi/sni
// * http/ws
// * irc
// * fallback to telnet
// At this piont we've already at least one byte via Peek()
// so the first packet is available in the buffer
// Note: Realistically no tls/http/irc client is going to send so few bytes
// (and no router is going to chunk so small)
// that it cannot reasonably detect the protocol in the first packet
// However, typical MTU is 1,500 and HTTP can have a 2k URL
// so expecting to find the "HTTP/1.1" in the Peek is not always reasonable
n := conn.Buffered()
firstMsg, err := conn.Peek(n)
if nil != err {
conn.Close()
return
}
var protocol string
// between A and z
if firstMsg[0] >= 65 && firstMsg[0] <= 122 {
i := bytes.Index(firstMsg, []byte(" /"))
if -1 != i {
protocol = "HTTP"
// very likely HTTP
j := bytes.IndexAny(firstMsg, "\r\n")
if -1 != j {
k := bytes.Index(bytes.ToLower(firstMsg[:j]), []byte("HTTP/1"))
if -1 != k {
// positively HTTP
}
}
}
} else if 0x16 /*22*/ == firstMsg[0] {
// Because I don't always remember off the top of my head what the first byte is
// http://blog.fourthbit.com/2014/12/23/traffic-analysis-of-an-ssl-slash-tls-session
// https://tlseminar.github.io/first-few-milliseconds/
// TODO I want to learn about ALPN
protocol = "TLS"
}
if "" == protocol {
fmt.Fprintf(conn, "\n\nWelcome to Sample Chat! You're not an HTTP client, assuming Telnet.\nYou must authenticate via email to participate\n\nEmail: ")
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wantsServerHello <- conn
return
} else if "HTTP" != protocol {
defer conn.Close()
fmt.Fprintf(conn, "\n\nNot yet supported. Try HTTP or Telnet\n\n")
return
}
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demuxHttpClient <- conn
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}
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func handleConnection(netConn net.Conn) {
ts := time.Now()
fmt.Fprintf(os.Stdout, "[New Connection] (%s) welcome %s\n", ts, netConn.RemoteAddr().String())
m := sync.Mutex{}
virgin := true
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bufConn := newBufferedConn(netConn)
go func() {
// Handle First Packet
_, err := bufConn.Peek(1)
//fmsg, err := bufConn.Peek(1)
if nil != err {
panic(err)
}
//fmt.Fprintf(os.Stdout, "[First Byte] %s\n", fmsg)
m.Lock()
if virgin {
virgin = false
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gotClientHello <- bufConn
} else {
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wantsServerHello <- bufConn
}
m.Unlock()
}()
time.Sleep(250 * 1000000)
// If we still haven't received data from the client
// assume that the client must be expecting a welcome from us
m.Lock()
if virgin {
virgin = false
// don't block for this
// let it be handled after the unlock
defer fmt.Fprintf(netConn,
"\n\nWelcome to Sample Chat! You appear to be using Telnet (http is also available on this port)."+
"\nYou must authenticate via email to participate\n\nEmail: ")
}
m.Unlock()
}
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func sendAuthCode(cnf ConfMailer, to string) (string, error) {
code, err := genAuthCode()
if nil != err {
return "", err
}
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// TODO use go text templates with HTML escaping
text := "Your authorization code:\n\n" + code
html := "Your authorization code:<br><br>" + code
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// https://stackoverflow.com/questions/24493116/how-to-send-a-post-request-in-go
// https://stackoverflow.com/questions/16673766/basic-http-auth-in-go
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client := http.Client{}
form := url.Values{}
form.Add("from", cnf.From)
form.Add("to", to)
form.Add("subject", "Sample Chat Auth Code: "+code)
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form.Add("text", text)
form.Add("html", html)
req, err := http.NewRequest("POST", cnf.Url, strings.NewReader(form.Encode()))
if nil != err {
return "", err
}
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//req.PostForm = form
req.Header.Add("User-Agent", "golang http.Client - Sample Chat App Authenticator")
req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
req.SetBasicAuth("api", cnf.ApiKey)
resp, err := client.Do(req)
if nil != err {
return "", err
}
defer resp.Body.Close()
// Security XXX
// we trust mailgun implicitly and this is just a demo
// hence no DoS check on body size for now
body, err := ioutil.ReadAll(resp.Body)
if nil != err {
return "", err
}
if resp.StatusCode < 200 || resp.StatusCode >= 300 || "{" != string(body[0]) {
fmt.Fprintf(os.Stdout, "[Mailgun] Uh-oh...\n[Maigun] Baby Brent says: %s\n", body)
} else {
fmt.Fprintf(os.Stdout, "[Mailgun] Status: %d", resp.StatusCode)
}
return code, nil
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}
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type myHttpServer struct {
chans chan bufferedConn
net.Listener
}
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func (m *myHttpServer) Accept() (net.Conn, error) {
bufConn := <-m.chans
return bufConn, nil
}
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func newHttpServer(l net.Listener) *myHttpServer {
return &myHttpServer{make(chan bufferedConn), l}
}
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var config Conf
func serveStatic(req *restful.Request, resp *restful.Response) {
actual := path.Join(config.RootPath, req.PathParameter("subpath"))
fmt.Printf("serving %s ... (from %s)\n", actual, req.PathParameter("subpath"))
http.ServeFile(
resp.ResponseWriter,
req.Request,
actual)
}
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func serveHello(req *restful.Request, resp *restful.Response) {
fmt.Fprintf(resp, "{\"msg\":\"hello\"}")
}
// TODO I probably should just make the non-exportable properties private/lowercase
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type authReq struct {
Cid string `json:"cid"`
ChallengedAt time.Time `json:"-"`
Chan chan authReq `json:"-"`
Otp string `json:"otp"`
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CreatedAt time.Time `json:"-"`
DidAuth bool `json:"-"`
Subject string `json:"sub"` // Subject as in 'sub' as per OIDC
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VerifiedAt time.Time `json:"-"`
Tries int `json:"-"`
}
func requestAuth(req *restful.Request, resp *restful.Response) {
ar := authReq{
CreatedAt: time.Now(),
DidAuth: false,
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Tries: 0,
}
// Not sure why go restful finds it easier to do ReadEntity() than the "normal" way...
// err := json.NewDecoder(req.Body).Decode(&ar)
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err := req.ReadEntity(&ar)
if nil != err {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"bad json in request body\"} }")
return
}
email := strings.TrimSpace(ar.Subject)
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emailParts := strings.Split(email, "@")
// TODO better pre-mailer validation (whitelist characters or use lib)
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if 2 != len(emailParts) {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"bad email address '"+email+"'\"} }")
return
}
ar.Subject = email
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var otp string
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if "" != config.Mailer.ApiKey {
otp, err = sendAuthCode(config.Mailer, ar.Subject)
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if nil != err {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"error sending auth code via mailgun\" } }")
return
}
}
if "" == otp {
otp, err = genAuthCode()
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if nil != err {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"error generating random number (code)\"} }")
return
}
}
ar.Otp = otp
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// Cheat code in case you didn't set up mailgun keys
fmt.Fprintf(os.Stdout, "\n== HTTP AUTHORIZATION ==\n[cheat code for %s]: %s\n", ar.Subject, ar.Otp)
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cid, _ := genAuthCode()
if "" == cid {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"error generating random number (cid)\"} }")
}
ar.Cid = cid
newAuthReqs <- ar
// Not sure why this works... technically there needs to be some sort of "end"
// maybe it just figures that if I've returned
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fmt.Fprintf(resp, "{ \"success\": true, \"cid\": \""+ar.Cid+"\" }")
}
func issueToken(req *restful.Request, resp *restful.Response) {
ar := authReq{}
cid := req.PathParameter("cid")
if "" == cid {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"bad cid in request url params\"} }")
return
}
//err := json.NewDecoder(r.Body).Decode(&ar)
err := req.ReadEntity(&ar)
if nil != err {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"bad json in request body\"} }")
return
}
ar.Cid = cid
ar.Chan = make(chan authReq)
valAuthReqs <- ar
av := <-ar.Chan
close(ar.Chan)
ar.Chan = nil
// TODO use a pointer instead?
if "" == av.Otp {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"invalid request: empty authorization challenge\"} }")
return
}
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av.Tries += 1
av.ChallengedAt = time.Now()
// TODO security checks
// * ChallengedAt was at least 1 second ago
// * Tries does not exceed 5
// * CreatedAt is not more than 15 minutes old
// Probably also need to make sure than not more than n emails are sent per y minutes
// Not that this would even matter if the above were implemented, just a habit
if 1 != subtle.ConstantTimeCompare([]byte(av.Otp), []byte(ar.Otp)) {
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fmt.Fprintf(resp, "{ \"error\": { \"message\": \"invalid authorization code\"} }")
// I'm not sure if this is necessary, but I think it is
// to overwrite the original with the updated
// (these are copies, not pointers, IIRC)
// and it seems like this is how I might write to a DB anyway
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newAuthReqs <- av
return
}
av.DidAuth = true
ar.VerifiedAt = time.Now()
newAuthReqs <- av
// TODO I would use a JWT, but I need to wrap up this project
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fmt.Fprintf(resp, "{ \"success\": true, \"token\": \""+ar.Cid+"\" }")
}
func requireToken(req *restful.Request, resp *restful.Response, chain *restful.FilterChain) {
ar := authReq{}
auth := req.HeaderParameter("Authorization")
if "" == auth {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"missing Authorization header\"} }")
return
}
authParts := strings.Split(auth, " ")
if "bearer" != strings.ToLower(authParts[0]) || "" == authParts[1] {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"expected 'Authorization: Bearer <Token>'\"} }")
return
}
ar.Cid = authParts[1]
ar.Chan = make(chan authReq)
valAuthReqs <- ar
av := <-ar.Chan
close(ar.Chan)
ar.Chan = nil
// TODO use a pointer instead?
if "" == av.Cid {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"invalid token: no session found\"} }")
return
}
// I prefer testing for "if not good" to "if bad"
// (much safer in the dynamic world I come from)
if true != av.DidAuth {
fmt.Fprintf(resp, "{ \"error\": { \"message\": \"bad session'\"} }")
return
}
req.SetAttribute("user", av.Subject)
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chain.ProcessFilter(req, resp)
}
func listMsgs(req *restful.Request, resp *restful.Response) {
// TODO support ?since=<ISO_TS>
// Also, data race? the list could be added to while this is iterating?
// For now we'll just let the client sort the list
resp.WriteEntity(&JsonMsg{
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Messages: myChatHist.msgs[:myChatHist.c],
})
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}
func postMsg(req *restful.Request, resp *restful.Response) {
user, ok := req.Attribute("user").(string)
if !ok {
fmt.Fprintf(resp, "{ \"error\": { \"code\": \"E_SANITY\", \"message\": \"SANITY FAIL user was not set, nor session error sent\"} }")
return
}
if "" == user {
fmt.Fprintf(resp, "{ \"error\": { \"code\": \"E_SESSION\", \"message\": \"invalid session\"} }")
return
}
msg := myMsg{}
err := req.ReadEntity(&msg)
if nil != err {
fmt.Fprintf(resp, "{ \"error\": { \"code\": \"E_FORMAT\", \"message\": \"invalid json POST\"} }")
return
}
msg.sender = nil
msg.ReceivedAt = time.Now()
msg.User = user
if "" == msg.Channel {
msg.Channel = "general"
}
if "" == msg.Message {
fmt.Fprintf(resp, "{ \"error\": { \"code\": \"E_FORMAT\", \"message\": \"please specify a 'message'\"} }")
return
}
broadcastMsg <- msg
fmt.Fprintf(resp, "{ \"success\": true }")
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}
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func main() {
flag.Usage = usage
port := flag.Uint("telnet-port", 0, "tcp telnet chat port")
confname := flag.String("conf", "./config.yml", "yaml config file")
flag.Parse()
confstr, err := ioutil.ReadFile(*confname)
fmt.Fprintf(os.Stdout, "-conf=%s\n", *confname)
if nil != err {
fmt.Fprintf(os.Stderr, "%s\nUsing defaults instead\n", err)
confstr = []byte("{\"port\":" + strconv.Itoa(int(*port)) + "}")
}
err = yaml.Unmarshal(confstr, &config)
if nil != err {
config = Conf{}
}
if "" == config.RootPath {
// TODO Embed the public dir at the default
config.RootPath = "./public"
}
// The magical sorting hat
newConns = make(chan net.Conn, 128)
// TCP & Authentication
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myRawConns := make(map[bufferedConn]tcpUser)
wantsServerHello = make(chan bufferedConn, 128)
authTcpChat = make(chan tcpUser, 128)
// HTTP & Authentication
myAuthReqs := make(map[string]authReq)
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newAuthReqs = make(chan authReq, 128)
valAuthReqs = make(chan authReq, 128)
delAuthReqs = make(chan authReq, 128)
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gotClientHello = make(chan bufferedConn, 128)
demuxHttpClient = make(chan bufferedConn, 128)
// cruft to delete
//myRooms = make(map[string](chan myMsg))
//myRooms["general"] = make(chan myMsg, 128)
// Note: I had considered dynamically select on channels for rooms.
// https://stackoverflow.com/questions/19992334/how-to-listen-to-n-channels-dynamic-select-statement
// I don't think that's actually the best approach, but I just wanted to save the link
broadcastMsg = make(chan myMsg, 128)
// Poor-Man's container/ring (circular buffer)
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myChatHist.msgs = make([]*myMsg, 128)
msgIndex := 0
var addr string
if 0 != int(*port) {
addr = ":" + strconv.Itoa(int(*port))
} else {
addr = ":" + strconv.Itoa(int(config.Port))
}
// https://golang.org/pkg/net/#Conn
sock, err := net.Listen("tcp", addr)
if nil != err {
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fmt.Fprintf(os.Stderr, "Couldn't bind to TCP socket %q: %s\n", addr, err)
os.Exit(2)
}
fmt.Println("Listening on", addr)
go func() {
for {
conn, err := sock.Accept()
if err != nil {
// Not sure what kind of error this could be or how it could happen.
// Could a connection abort or end before it's handled?
fmt.Fprintf(os.Stderr, "Error accepting connection:\n%s\n", err)
}
newConns <- conn
}
}()
// Learning by Example
// https://github.com/emicklei/go-restful/blob/master/examples/restful-multi-containers.go
// https://github.com/emicklei/go-restful/blob/master/examples/restful-basic-authentication.go
// https://github.com/emicklei/go-restful/blob/master/examples/restful-serve-static.go
// https://github.com/emicklei/go-restful/blob/master/examples/restful-pre-post-filters.go
container := restful.NewContainer()
wsStatic := new(restful.WebService)
wsStatic.Path("/")
wsStatic.Route(wsStatic.GET("/").To(serveStatic))
wsStatic.Route(wsStatic.GET("/{subpath:*}").To(serveStatic))
container.Add(wsStatic)
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cors := restful.CrossOriginResourceSharing{ExposeHeaders: []string{"Authorization"}, CookiesAllowed: false, Container: container}
wsApi := new(restful.WebService)
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wsApi.Path("/api").Consumes(restful.MIME_JSON).Produces(restful.MIME_JSON).Filter(cors.Filter)
wsApi.Route(wsApi.GET("/hello").To(serveHello))
wsApi.Route(wsApi.POST("/sessions").To(requestAuth))
wsApi.Route(wsApi.POST("/sessions/{cid}").To(issueToken))
wsApi.Route(wsApi.GET("/rooms/general").Filter(requireToken).To(listMsgs))
wsApi.Route(wsApi.POST("/rooms/general").Filter(requireToken).To(postMsg))
container.Add(wsApi)
server := &http.Server{
Addr: addr,
Handler: container,
}
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myHttpServer := newHttpServer(sock)
go func() {
server.Serve(myHttpServer)
}()
// Main event loop handling most access to shared data
for {
select {
case conn := <-newConns:
// This is short lived
go handleConnection(conn)
case u := <-authTcpChat:
// allow to receive messages
// (and be counted among the users)
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myRawConns[u.bufConn] = u
// is chan chan the right way to handle this?
u.userCount <- len(myRawConns)
broadcastMsg <- myMsg{
sender: nil,
// TODO fmt.Fprintf()? template?
Message: "<" + u.email + "> joined #general\n",
ReceivedAt: time.Now(),
Channel: "general",
User: "system",
}
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case ar := <-newAuthReqs:
myAuthReqs[ar.Cid] = ar
case ar := <-valAuthReqs:
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// TODO In this case it's probably more conventional (and efficient) to
// use struct with a mutex and the authReqs map than a chan chan
av, ok := myAuthReqs[ar.Cid]
//ar.Chan <- nil // TODO
if ok {
ar.Chan <- av
} else {
ar.Chan <- authReq{}
}
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case ar := <-delAuthReqs:
delete(myAuthReqs, ar.Cid)
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case bufConn := <-wantsServerHello:
go handleTelnetConn(bufConn)
case u := <-delTcpChat:
// we can safely ignore this error, if any
u.bufConn.Close()
delete(myRawConns, u.bufConn)
case bufConn := <-gotClientHello:
go muxTcp(bufConn)
case bufConn := <-demuxHttpClient:
// this will be Accept()ed immediately by the go-restful container
// NOTE: we don't store these HTTP connections for broadcast
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// since we manage the session by HTTP Auth Bearer rather than TCP
myHttpServer.chans <- bufConn
case msg := <-broadcastMsg:
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// copy comes in, pointer gets saved (and not GC'd, I hope)